Note: Descriptions are shown in the official language in which they were submitted.
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DETAILED DESCRIPTION OF THE I~VE~TION
The present inventiGn relates to an air mat
apparatus which is mainly laid on a bed or chair or wound
round a hand or leg in order to promote the blood circu-
lation or the body surface, to prevent bedsores or to
massage the waist, back, hand, leg or the like, and relates
especially to an air mat apparatus in which the pressure
applied on the body surface is easily changealbe.
Prior Art
An air mat in which compressed air is introduced
into an airtight bag has been already put to practical use.
However, an air mat the whole surface of which is always
pushed by air pressure hinders the blood circulation at the
human body surface when used. This is not limited to such
an air mat but also an air mat formed of urethane foam has
the same disadvantage. Therefore, patients who cannot move
on the bed e.g. those in seriously illness or affected by
an atrophy of muscles have bedsores and suffer from the
weakening of internal organs, especially digestive organ
like intestines. In order to prevent this, a new bed has
been developed. The bed has two tilting plates on either
side, and by alternately tilting each of the tilting plates,
the patient on the bed is moved aside at a given time's
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interval. But such a bed is expensive because the structure
for shifting the upper surface of the bed is complicated,
and since such a structure cannot be easily mounted on a
conventional bed, it has been designed for exclusive use.
Further disadvantageously, such a bed is apt tO cause mechan-
ical noises when tilted. Furthermore, in such a bed provided
with tilting plates, it is structurally difficult to partially
change the pressing force applied on the body surface by
the bed, and thus all the patient cannot use the bed in the
best condition and the use is remarkably limited. In an
apparatus for promoting blood circulation by pressing parts
of the human body surface, it is preferable that the pressure
applied on the body surface is adjustable in accordance
with the use purpose, liking of the user, the way of use and
the like. The inflation and deflation of the parts of an
air mat can be adjustable by connecting the devided airtight
chambers of the mat through separate electromagnetic valves
to an air source and controlling each electromagnetic valve
for example, by means of timers. According to this system,
however, such an air mat costs very high since a number of
expensive electromagnetic valves are required. Besides, loud
noises generate when the valves are opened or closed, and
such an air mat is not suitable for practical use.
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~rief Sul~nary of the Invention
The present invention is developed in order to
eliminate all of tne abovementioned disadvantages of the
conventional air mat. An important object of the present
invention is to provide an air mat in which the whole body
and the changeover valves are simple in structure and
inexpensive noises hardly generate when the changeover
valves are operated; the pressure applied on the human body
by the mat is adjustable by simple operations: a number of
airtight chambers can be controlled by a single changeover
valve, and which is durable, trouble-freè, and easily
maintained and treated.
The above and further objects and novel features
of the invention will more fully appear from the following
detailed description when the same is read in connection
with the accompanying drawing. It is to be expressly understood,
however, that the drawing is for purpose of illustration
only and is not intended as a definition of the limits of
the invention.
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Detailed Description
Now, examples of the present invention will be
described blow with reference to the appended drawings, in
which:
Fig. 1 is a schematic plan view of an example of
the air mat apparatus according to the present invention;
Fig. 2 is a sectional view showing the connection
between the airtight bags and the air pipe;
Fig. 3 is a side view showing the air mat apparatus
in used state;
Fig. 4 is a perspective view of the air mat apparatus
in another used state;
Fig. 5 is a plan view of a mat body to be wound
round an arm or legi
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~ ig. 6 is an enlarged sectional view of the important
portion of the mat body;
Fig. 7 is a longitudinal sectional view of the valve
body;
Fig. 8 is an exploded view of the air inlet and out-
let recesses;
Fig. 9, 10 are lateral sectional views of the valve
body showning examples of the connection between the valve
body and the mat body;
Fig. 11, 12 are perspective views of other examples
of the changeover elements;
Fig. 13 is a sectional view of the changeover element
inserted in the casing; and
Fig. 14, 15 are sectional views of the connectors
connected in the way of the air pipe.
An air mat apparatus shown in Fig. 1 comprises a
mat body 1, an air source for feeding the mat body 1 with
pressed air, and a changeover valve 2 connected between the
mat body 1 and the air source.
The mat body l comprises a number of tubular air-
tight bags each defining an airtight chamber, and a cover 4
in which the airtight bags are contained in grid-like
arrangement. The airtight bags 3 are formed of natural or
synthetic rubber-like resilient material or flexible synthetic
resin sheet so that they can be inflated and deflated.
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Th~ co~er 4 is rormed ~y sewing into sha~e of nonresilient
or subs~alltially nonresilient sheet material such as cloth
so that the dimensions of the inflated airtight bags are
limited to a constant values even if the pressure of the
introduced air somewhat changed. The preferred dimensions
of the airtight bag 3 is decided to be optimum values in
accordance with the use purpose, but usually the outer
diameter of the inflated airtight bag is selected as 2 to
lOcm~ while the length thereof is 30 to 150cm. To one end
of the airtight bag 3, a short rigid tube 5 is fixed in an
airtight manner as shown in Fig. 2, and an air pipe 6 is
fitted on the tube 5 so as to be connected thereto.
When the air mat apparatus is laid on a bed as shown
in Fig. 3, the dimensions of the airtight bags 3 are preferably
selected so that the length of the airtight bags 3 corresponding
to the human body is much larger than the breadth of a user's
shoulders and the diameter of the airtight bags corresponding
to the waist is somewhat large while that corresponding to
the shoulder blades is somewhat small.
When a mat body 1 is to be wound round an arm as
shown in Fig. 4 or a leg (not shown), the airtight bags are
in grid-like arrangement as shown in Fig. 5 so that each
airtight bag is wound round the arm or leg, that is, the
airtight bags are in the lateral direction with respect to
the length of the arm or leg.
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Fig. 6 shows the sectional view of the cover 4.
The cover 4 comprises two sheets of cloth connected by sewing
so as to define container sections for the airtight bags
arranged grid-like manner. The whole shape of the mat body 1
must not change whether the airtight bags are inflated or
deflated. In order to realize this, in the cover 4, the lower
sheet is laid in plane and the upper sheet in a laminated
form is connect by sewing onto the lower sheet. Therefore,
when the airtight bags are inflated, only the upper sheet
of the cover is expanded.
The distance between two adjacent airtight bags
is selected to be shorter than half the sum of the diameters
of the two adjacent airtight bags. This is shown in Fig. 6.
In Fig. 6, the distance W between the center of the airtight
bag 3 at the center and the adjacent airtight bag 3 is e.g.
several milimeter shorter than half the sum of the diameters
dl, d2 of the central airtight bag 3 and the adjacent airtight
bag 3 respectively.
With this shape, when a plurality of airtight bags
are inflated, an airtight bag 3 is pushed by the lateral
pressure the adjacent airtight bags 3 and the side surface
is recessed. This recess generates an upward pushing force
of the airtight bag 3; Consequently, the airtight bag 3 in
the middle portion becomes higher and the whole of the airtight
bag is in the shape of an arc. Thus, the human body surface
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is erfectively pushed and at the same time, the recesses
defined between inflated airtight bags 3 are reduced.
The container section 7 o~ the cover 4 is opened
or can be opened at one end. The airtight bag 3 is inserted
into the container section and it can also taken out. The
air pipe 6 is removably connected to the tube 5 of the
airtight bag 3. If an airtight bag comes in trouble during
the time of use, it is taken out of the container section 7
of the cover 4 and a new one is inserted thereinto to which
the air pipe is reconnected.
As the air source, an air pressure pump 8 of 50
to 300mmHg discharge pressure or a combination of a reduc-
tion valve 9 and a pressure air tank 10. When the pressure
air tank 10 is used, high pressure air in the tank 10 is
reduced to 50 tO 300mmHg by means of the reduction valve 9
and then fed into the airtight bags.
The airtight bags 3 can be deflated only by commu-
nicating the airtight bags through the changeover valve 2
with the discharge side so that the airtight bags are opened
to the outer air. However, it is preferable that the airtight
bags are compulsorily deflated by discharging air out of
the airtight bags by means of an air discharge pump. For
this purpose, an air discharge pump 11 and the air source
are connected to the changeovervalve- 2.
The changeover valve 2 comprises a valve body 12
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and a drive motor 13 for driving the valve body 12. The valve
body 12 ccmprises a changeover element 14 adapted to be
rotated by the drive motor 13 and a casing 15 into which the
changeover valve is rotatably inserted.
The changeover element 14 is provided with a
diaphragm 29 having a circular outer periphery. The outer
circumferencial surface of the diaphragm 29 is in airtight
contact with the inner surface of the casing 15 and slidable
in the casing 15. An air inlet recess 15 is provided on one
side of the diaphragm 29 and an air outlet recess 17 on the
other side thereof. The air inlet recess 16 and air outlet
recess 17 are provided adjacent to each other in the direction
of the rotation of the changeover element 14 so that through
the rotation of the changeover element 14, an air outlet
opening 18 provided in the casing 15 can be alternately
communicated with either of the air inlet and outlet recesses
16, 17.
In the valve body 12 shown in Figs. 7 to lO, the
ratio between the inflation and deflation times of the
airtight bags can be changed by displacing the casing 15
in the axial direction. That is, the number of the airtight
bags to be inflated as a group can be changed.
Fig. 8 is an exploded view showing the air inlet
recess 16, the air outlet recess 17 and the diaphragm 29.
In this figure, the air inlet recess 16 is so fomed that
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it becomes narrower in the axial lirection and has a tapered
end. T~e air outlet recess 17 is provided adjacent to the air
inlet recess 16 and circumferentially spaced from the latter
by the width S of the diaphragm 29. The width of the air
outlet recess 17 changes in the axial direction.
The air inlet and outlet recesses 16, 17 are
separately communicated with introduction recesses 19, 20
respectively so that the air inlet recess 16 is always
communicated with the air source and the air outlet recess
17 is always communicated with the air discharge pump 11.
The introduction recesses 19, 20 are provided on either
side of the air inlet and outlet recesses 16, 17 and throughout
the outer circumference of the changeover element 14.
As shown in Fig. 1, one end of the changeover
element 14 is connected to the drive motor 13 by coupling
21 so that the changeover time can be controlled by changing
the rotation number of the drive motor 13.
The casing 15 is formed of a cylinder with two ends
opened into which the changeover element 14 can be airtightly
and rotatably inserted. In Fig. 7, the right side end of
the casing 15 is inserted by means of a key 22 or spline
into a fitting stand 23 so as not to rotate but to slide
in the axial direction. Further, at the right side end of
the casing 15, an external screw is provided on the outer
circumferential surface. Furthermore, air openings 18 uniformly
spaced in the circumferential direction of the casing 15
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are provided and each air opening penetrates the casing 15
in the radial direction. On either side of the air openings,
an ai.- inlet opening 24 and an air outlet opening 25 are
provided.
The air openings 18 are arranged in correspondance
with the locus of the displacement of the diaphragm inter-
posed between the air inlet and outlet recesses 16, 17 on
the outer surface of the changeover element. The air inlet
opening 24 is posi.tioned in correspondance with the intro-
duction recess 19 communicated with the air inlet recess 16,
while the air outlet opening 25 is positioned in correspondance
with the introduction recess 20 communicated with the air
outlet recess 17~
The external screw of the casing 15 is in the
threaded engagement with the internal screw provided in a
tongue 26. The tongue 26 is fitted through a setscrew 27
to the fitting stand 23 so as to be rotatable but not movable
in the axial direction. Therefore, on the outer circumferential
surface of the fitting stand 23, an annular groove 28 is
provided in which the setscrew 27 slides.
With the rotation of the tongue 26, the casing 15
is displaced in the axial direction and the positions at
which the air opening 18 pass the air inlet recess 16 and
the air outlet recess 17 change, whereby the state of the
communication of the air opening 18 with the air inlet and
outlet recesses 16, 17.
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~ n Fig. 7, when the casing 15 is displaced to the
righ~, the nu~er of the air openings 18 communicated with
the air inlet recess lo decreases, and the inflated airtight
bags decreases in number.
When the casing 1~ is displaced to the rightmost
position, less than one air opening 18 is communicated w~th
the air inlet recess 16.
In the changeover valve shown in Fig. 7, with the
displacement of the casing 15 in the axial direction, the
casing 15 and the changeover valve are relatively displaced
in the axial direction. However, if the changeover element
is displaced in the axial direction with respect to the casing,
the same movement can be obtained. In this case, though not
shown, a drive motor connected to the changeover element
is fitted to a base so as to be movable in the axial direction,
and the changeover element is displaced together with the
drive motor.
The air opening 18 is connected through the air pipe
6 to the airtight bags 3, and the air inlet opening 24 is
connected to the air source, w~lile the air outlet opening 25
is opened ~o the outer air or connected to the air discharge
pump 11.
Fiys. 11 to 13 show other changeover elements 14
having different structures.
Tn the c~angeover element 14 shown in Fig. 11,
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two discs 31, 32 are fixed at both ends of a shaft 30 so
that the outer circumferences of the discs are in airtight
contact with the inner surface of the casing. Between the
two discs 31, 32, the diaphragm 29 the outer periphery of
which is in airtight contact with the inner surface of the
casing is inclinedly fixed. And the air inlet and outlet
recesses 16, 17 are interposed between the diaphragm 29
and the discs 31, 32 respectively.
In a cylinder into which the changeover element
14 is inserted, the inlet opening is provided so as to be
communicated with the air inlet recess 16 and the air outlet
opening is provided so as to be communicated with the air
outlet recess 17, while the air opening is provided in the
sliding surface of the outer periphery of the diahpragm 29.
In the changeover element 14 shown in Fig. 12, two
discs 31, 32 are fixed at both ends of the thick shaft 30
and the diaphragm 29 is inclinedly fixed between the discs
31, 32. The discs 31, 32 and the diapharagm 29 have such
diameters respectively that they can rotate with their outer
circumferential surface being in airtight contact with the
inner surface of the casing 15 as shown in Fig. 13.
It is advantageous that the changeover element 14
shown in Figs. 12, 13 can be easily manuractured.
In usual use, air openings 18 are successively
connected to the airtight bags 3 as shown in Fig. 9.
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In order to slowly rotate the changeover element
14 and thus to raise the speed of displacement of the
inflated airtight bags 3, the neibouring air openings 18
are connected to the airtight bags at a few bags apart as
shown in ~ig. 10.
If the airtight bags are more than the air openings
in number, a plurality of airtight bags are connected to
an air opening.
The air pipe 6 is removably connected to the change-
over element 12, so that the inflated or deflated states
of the airtight bags can be changed by changing the connec-
tion of the air pipe to the changeover element 12. The air
pipe 6 is formed of a flexible synthetic resin tube.
- As shown in Figs. 14, 15, it is possible that a
connecting means 33 is connected in the way of the air pipe
6 and the connection of the air pipe 6 is changed by the
connecting means 33.
The connecting means 33 comprises a body 33A to
both ends of which air pipe is connected, and a slider 33B
removably and airtightly fitted to the body 33A.
The body 33A is formed of a cylinder into which
the slider 33 is inserted. Opposed air openings 34 are opened
into the hollow of the body 33~. The slider 35 is provided
with communication bores which can communicate the opposed
air openings 34 with each other when the slider 35 is inserted
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into the body 33A. lrhe communication bores are provided in
parallel as shown in ~ig. 14 or provided to penetrate through
the slider 33B according a given rule and without any commu-
nication with one another. By changins the pushing condition
of the slider 33B, the connection between the changeover
~alve 2 and the mat body 1 is changed and the inflation and
deflation of the mat body 1 is controlled.
In the air mat apparatus having the abovementioned
structure, the changeover valve connected between the mat
body and the air source comprises the drive motor and the
valve body, the valve body comprising the changeover element
driven by the drive motor and the casing in which the change-
over element rotates in the airtight manner, the changeover
element being provided on its outer circumferential surface
with the air inlet recess and the air outlet recess neibouring
to but not communicated with each other, the boundary of
the air inlet and outlet recesses being inclined in the
direction of the circu~ference of the changeover element,
thus the widths of the air inlet and outlet recesses changing
toward the circumference of the changingover element so that
as the air inlet recess becomes broader the air outlet
recess becomes narrower, on the o-ther hand, the casing into
which the changeover element is rotatably inserted being
provided with a plurality of air openings in correspondence
with the air inlet and outlet recesses, and the casing being
fitted so as not to rotate but to move in th~ axial direc~ion,
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and ~herefore, by displacing the casing in the axial direction
ar.d rotating the changeover element, the state of the commu-
nication of the air openings with the air inlet and outlet
recesses can be changed. Consequently, by displacing the
casing in the axial direction, the numbers of the inflated
and deflated airtight.bags connected to the air openings
can be changed, and the user can conveniently use the air
mat apparatus always at the most suitable condition for his
liking, and the way and purpose of use.
Further, in this air mat apparatus, the mat body
is divided into a plurality of defined airtight chambers,
air being introduced under pressure out of the airtight
chambers and discharged therefrom so as to inflate and
deflate the airtight bags, further, the changeover valve
comprising a casing into which a changeover element provided
with two recesses is inserted and rotated, and therefore,
the structures of the whole apparatus and the changeover
valve being simplified and manufactured at low cost, the
changeover valve, unlike an electromagnetic valve, never
generating any uncomfortable noises when operated, that is,
the air mat apparatus being operated quietly, the pusing
force applied to the human body surface being easily controlled
only by displacing the casing, a number of airtight chambers
being controlled by means of a single changeover valve, and
further, the air mat apparatus can realize many effects such
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as durability, troublerree ~uality and so forth superior
to other air mat apparatus.
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